NOTE: if you have already changed your password using the password change online form while off-campus, your old password will still be required to login to your BU laptop until it is brought back to campus.
To fix this, you will need to either change your password again using this method or bring your computer to campus and login with your new password to update the login credentials on your laptop so it can use your new password.
Until you do either of these, you will need to login on your BU laptop using your old password, while all the other BU services will be using your new password.